Array.GetUpperBound Method (System)

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.NET Framework Class Library
Array.GetUpperBound Method

Updated: June 2010

Gets the upper bound of the specified dimension in the Array.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Visual Basic
Public Function GetUpperBound ( _
	dimension As Integer _
) As Integer
C#
public int GetUpperBound(
	int dimension
)
Visual C++
public:
int GetUpperBound(
	int dimension
)
F#
member GetUpperBound : 
        dimension:int -> int

Parameters

dimension
Type: System.Int32
A zero-based dimension of the Array whose upper bound needs to be determined.

Return Value

Type: System.Int32
The upper bound of the specified dimension in the Array.
Exceptions
Exception Condition
IndexOutOfRangeException

dimension is less than zero.

-or-

dimension is equal to or greater than Rank.
Remarks

GetUpperBound(0) returns the upper bound for the indexes of the first dimension of the Array, and GetUpperBound(Rank - 1) returns the upper bound of the last dimension of the Array.

The GetUpperBound method is not affected by the number of elements in the array if the array is empty. The value of the Length property can never be greater than the number of elements allowed, as determined by the upper bound. For example, an array with an upper bound of 10 elements can never have a length greater than 9 (0 represents the first element).

This method is an O(1) operation.

Examples

The following code example uses GetLowerBound and GetUpperBound to initialize a one-dimensional array and a multidimensional array.

Visual Basic

Imports System
Imports Microsoft.VisualBasic

Public Class SamplesArray    

    Public Shared Sub Main()

        ' Creates a new one-dimensional Array of type Int32.
        Dim my1DIntArray As Array = Array.CreateInstance(GetType(Int32), 5)

        ' Uses GetLowerBound and GetUpperBound in the for loop.
        Dim i As Integer
        For i = my1DIntArray.GetLowerBound(0) To my1DIntArray.GetUpperBound(0)
            my1DIntArray.SetValue(i + 1, i)
        Next i 
        ' Displays the bounds and values of the one-dimensional Array.
        Console.WriteLine("One-dimensional Array:")
        Console.WriteLine("Rank" + ControlChars.Tab + "Lower" _
           + ControlChars.Tab + "Upper")
        Console.WriteLine("{0}" + ControlChars.Tab + "{1}" _
           + ControlChars.Tab + "{2}", 0, my1DIntArray.GetLowerBound(0), _
           my1DIntArray.GetUpperBound(0))
        Console.WriteLine("Values:")
        PrintValues(my1DIntArray)
        Console.WriteLine()

        ' Creates a new three-dimensional Array of type Int32.
        Dim my3DIntArray As Array = _
           Array.CreateInstance(GetType(Int32), 2, 3, 4)

        ' Uses GetLowerBound and GetUpperBound in the for loop.
        Dim j, k As Integer
        For i = my3DIntArray.GetLowerBound(0) _
        To my3DIntArray.GetUpperBound(0)
            For j = my3DIntArray.GetLowerBound(1) _
            To my3DIntArray.GetUpperBound(1)
                For k = my3DIntArray.GetLowerBound(2) _
                To my3DIntArray.GetUpperBound(2)
                    my3DIntArray.SetValue(i * 100 + j * 10 + k, i, j, k)
                Next k
            Next j 
        Next i

        ' Displays the bounds and values of the multidimensional Array.
        Console.WriteLine("Multidimensional Array:")
        Console.WriteLine("Rank" + ControlChars.Tab + "Lower" _
           + ControlChars.Tab + "Upper")
        For i = 0 To my3DIntArray.Rank - 1
            Console.WriteLine("{0}" + ControlChars.Tab + "{1}" _
               + ControlChars.Tab + "{2}", i, my3DIntArray.GetLowerBound(i), _
               my3DIntArray.GetUpperBound(i))
        Next i
        Console.WriteLine("Values:")
        PrintValues(my3DIntArray)
    End Sub


    Public Shared Sub PrintValues(myArr As Array)
        Dim myEnumerator As System.Collections.IEnumerator = _
           myArr.GetEnumerator()
        Dim i As Integer = 0
        Dim cols As Integer = myArr.GetLength(myArr.Rank - 1)
        While myEnumerator.MoveNext()
            If i < cols Then
                i += 1
            Else
                Console.WriteLine()
                i = 1
            End If
            Console.Write(ControlChars.Tab + "{0}", myEnumerator.Current)
        End While
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' One-dimensional Array:
' Rank    Lower    Upper
' 0    0    4
' Values:
'     1    2    3    4    5
' 
' Multidimensional Array:
' Rank    Lower    Upper
' 0    0    1
' 1    0    2
' 2    0    3
' Values:
'     0    1    2    3
'     10    11    12    13
'     20    21    22    23
'     100    101    102    103
'     110    111    112    113
'     120    121    122    123
C#

 using System;
 public class SamplesArray  {

    public static void Main()  {

       // Creates a new one-dimensional Array of type Int32.
       Array my1DIntArray = Array.CreateInstance( typeof(Int32), 5 );

       // Uses GetLowerBound and GetUpperBound in the for loop.
       for ( int i = my1DIntArray.GetLowerBound(0); i <= my1DIntArray.GetUpperBound(0); i++ )
          my1DIntArray.SetValue( i+1, i );

       // Displays the bounds and values of the one-dimensional Array.
       Console.WriteLine( "One-dimensional Array:" );
       Console.WriteLine( "Rank\tLower\tUpper" );
       Console.WriteLine( "{0}\t{1}\t{2}", 0, my1DIntArray.GetLowerBound(0), my1DIntArray.GetUpperBound(0) );
       Console.WriteLine( "Values:" );
       PrintValues( my1DIntArray );
       Console.WriteLine();

       // Creates a new three-dimensional Array of type Int32.
       Array my3DIntArray = Array.CreateInstance( typeof(Int32), 2, 3, 4 );

       // Uses GetLowerBound and GetUpperBound in the for loop.
       for ( int i = my3DIntArray.GetLowerBound(0); i <= my3DIntArray.GetUpperBound(0); i++ )
          for ( int j = my3DIntArray.GetLowerBound(1); j <= my3DIntArray.GetUpperBound(1); j++ )
             for ( int k = my3DIntArray.GetLowerBound(2); k <= my3DIntArray.GetUpperBound(2); k++ )  {
                my3DIntArray.SetValue( (i*100)+(j*10)+k, i, j, k );
             }

       // Displays the bounds and values of the multidimensional Array.
       Console.WriteLine( "Multidimensional Array:" );
       Console.WriteLine( "Rank\tLower\tUpper" );
       for ( int i = 0; i < my3DIntArray.Rank; i++ )
          Console.WriteLine( "{0}\t{1}\t{2}", i, my3DIntArray.GetLowerBound(i), my3DIntArray.GetUpperBound(i) );
       Console.WriteLine( "Values:" );
       PrintValues( my3DIntArray );
    }


    public static void PrintValues( Array myArr )  {
       System.Collections.IEnumerator myEnumerator = myArr.GetEnumerator();
       int i = 0;
       int cols = myArr.GetLength( myArr.Rank - 1 );
       while ( myEnumerator.MoveNext() )  {
          if ( i < cols )  {
             i++;
          } else  {
             Console.WriteLine();
             i = 1;
          }
          Console.Write( "\t{0}", myEnumerator.Current );
       }
       Console.WriteLine();
    }
 }
 /*
 This code produces the following output.

 One-dimensional Array:
 Rank    Lower    Upper
 0    0    4
 Values:
     1    2    3    4    5

 Multidimensional Array:
 Rank    Lower    Upper
 0    0    1
 1    0    2
 2    0    3
 Values:
     0    1    2    3
     10    11    12    13
     20    21    22    23
     100    101    102    103
     110    111    112    113
     120    121    122    123
*/
Visual C++

using namespace System;
void PrintValues( Array^ myArr );
void main()
{
   // Creates a new one-dimensional Array instance of type Int32.
   Array^ my1DIntArray = Array::CreateInstance( Int32::typeid, 5 );

   // Uses GetLowerBound and GetUpperBound in the for loop.
   for ( int i = my1DIntArray->GetLowerBound( 0 ); i <= my1DIntArray->GetUpperBound( 0 ); i++ )
      my1DIntArray->SetValue( i + 1, i );

   // Displays the bounds and values of the one-dimensional Array.
   Console::WriteLine(  "One-dimensional Array:" );
   Console::WriteLine(  "Rank\tLower\tUpper" );
   Console::WriteLine(  "{0}\t{1}\t{2}", nullptr, my1DIntArray->GetLowerBound( 0 ), my1DIntArray->GetUpperBound( 0 ) );
   Console::WriteLine(  "Values:" );
   PrintValues( my1DIntArray );
   Console::WriteLine();

   // Creates a new three-dimensional Array instance of type Int32.
   Array^ my3DIntArray = Array::CreateInstance( Int32::typeid, 2, 3, 4 );

   // Uses GetLowerBound and GetUpperBound in the for loop.
   for ( int i = my3DIntArray->GetLowerBound( 0 ); i <= my3DIntArray->GetUpperBound( 0 ); i++ )
      for ( int j = my3DIntArray->GetLowerBound( 1 ); j <= my3DIntArray->GetUpperBound( 1 ); j++ )
         for ( int k = my3DIntArray->GetLowerBound( 2 ); k <= my3DIntArray->GetUpperBound( 2 ); k++ )
         {
            my3DIntArray->SetValue( (i * 100) + (j * 10) + k, i, j, k );
         }

   // Displays the bounds and values of the multidimensional Array.
   Console::WriteLine(  "Multidimensional Array:" );
   Console::WriteLine(  "Rank\tLower\tUpper" );
   for ( int i = 0; i < my3DIntArray->Rank; i++ )
      Console::WriteLine(  "{0}\t{1}\t{2}", i, my3DIntArray->GetLowerBound( i ), my3DIntArray->GetUpperBound( i ) );
   Console::WriteLine(  "Values:" );
   PrintValues( my3DIntArray );
}

void PrintValues( Array^ myArr )
{
   System::Collections::IEnumerator^ myEnumerator = myArr->GetEnumerator();
   int i = 0;
   int cols = myArr->GetLength( myArr->Rank - 1 );
   while ( myEnumerator->MoveNext() )
   {
      if ( i < cols )
      {
         i++;
      }
      else
      {
         Console::WriteLine();
         i = 1;
      }

      Console::Write(  "\t{0}", myEnumerator->Current );
   }

   Console::WriteLine();
}

/*
 This code produces the following output.

One-dimensional Array:
Rank    Lower   Upper
0       0       4
Values:
        1       2       3       4       5

Multidimensional Array:
Rank    Lower   Upper
0       0       1
1       0       2
2       0       3
Values:
        0       1       2       3
        10      11      12      13
        20      21      22      23
        100     101     102     103
        110     111     112     113
        120     121     122     123
*/
Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
See Also

Reference

Array Class
System Namespace
GetLowerBound
Rank
Change History

Date

History

Reason

June 2010

Added remarks about upper bound and array length.

Customer feedback.
Community Content

Medinoc
To put it simply
Lower Bound + Length - 1 = Upper Bound.

When the lower bound is zero, it means Upper Bound = Length - 1.

Bruce Hamilton - MSFT
(edit)
"The GetUpperBound method is not affected by the number of elements in the array of if the array is empty"

= = =
Fixed for the next update. Thanks for catching that.
Bruce Hamilton
MSFT